Air filter device



FIG. 1 is a front perspective view of an air filter device showing the new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a left side elevational view with the right side elevational view being a mirror image thereof;

FIG. 6 is a rear elevational view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for an air filter device, as shown and described. 